Heat exchanger



Sept. 0. 1940. J. H. mm. JR 7 2,214,053

HEAT CHANGER Pu: la a 10, 19's! INVENTOR Jose pizzva A ORNEYS types of UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to heat exchangers, and to a system and method ior utilizing noxious medi ms. v

Ma ky'arraiigements for this purpose have been devised and marketed, for example, in connecobject of the present invention is to .provide an tion ,with exhaust 'gas' heaters for automobiles and airplanes, but an ever-present danger from leakage .of the exhaust gas into the heated air stream as a result of defects in partition mem bershas heretofore attended their use; and an .flicient heat exchanger structure wherein it is inherently ,impossible for the" heat dispensing or absorbing fluid-to escape from its conduit into the fluid being treated: even thou h op'enings' may be formed through the partitioning members separating the fluids as a result of deterioration, faulty 'workmanshi or any other cause.

The invention .cont'empl tes the provision of separate conduits for two iiuid mediums, one or which is the hu id to be treated, and the other of I which is to be utilized for. its'heat dispensing or ,fluid being treated even though openings heat absorbing capabilitiesm the case may require. The two conduits are arranged at some point in heat exchange relation, and means are employed for providing a pressure diflerential between the fluids at the point of heat exchange contact in favor of the fluidto be treated, whereby the pressure diirenential will prevent entrance of the heat dispensing or absorbing fluidi'n'to the may occur in the members separating the two fluids.

In the drawing:

Fig. 1 is a fragmentary diagrammatic view of a motorexhaust' conduit and in; one embodimentof the invention;

Fig. 2 is a diagrammatic transverse section, on a larger scale, taken along line II II" of Fig.1; r 1

Fig. 3 is a fragmentary'plan of another form of structure in porated;

Fig. 4 is a longitudinal section taken substantially along line Iii-IV of Fig.3; A

Fig. 5 is a transverse section taken substantially along line VV of Fig. 3. I

The drawing illustratesas one adaptation of the invention a construction comprising a conduit for motor exhaust gases and a separate air.

- conduit which is connected in circuit with the passenger compartment of anautomobile, airplane" or other motor driven vehicle. These con- ,duits are arrangedin juxtaposed relation and in heat exchange contact. In accordancerwith heat dispensing orheat absorbing fluid a heater illustratwhich theinvention is incorthe present invention means' are employed to provide a pressure differential betweenthe two fluids in favor of, thev fluid to be treated. Ac-

cording to one form of the invention this pressure differential providing means is in the form :6

of a non-mechanical arrangement of parts such as for example having the portion of the ex- I haust conduit which, is immediately. adjacent the air conduit constricted in form and dimension toautomatically. cause .the' exhaust gases 10 therein to flow through the zone of juxtaposition at an increased velocity. This arrangement is for the purpose of reducing pressure of the exhaust gases in the zone where heat exchange is to take place, whereby, under normal conditions,

the pressure in the air chamber is greater than *the pressure in the exhaust gas conduit. Thus, 'if openings develop in the structure which separates the exhaust gases from the heated air,

there will nevertheless be no leakage of .gases from the exhaust gas conduit into the circulating air system. L

Referring particularly to Fig: 1, a conventional motor exhaust conduit I0 is provided with a deformed sectionl l which comprises a reducing 26 section l2, a constricted central portion I4, and an expanding portion 16. The deformed conduit member H may be formed as an integral part of J the conduit? ID, or as a separate ifnit adapted for connection at l5, by welding or in any'other 30 suitable manner, to the end portion of the conduit I0. The relationship of the constricted portion H to the expanding portion I will, upon movement of gases through the con uit in the direction indiatedibydhe arrows, produce in the exhaust gas occupying the constricted portion H a pressure that is less than the pressure in thegas at the end portion ll of the expand Ting portion 16 and the portion ID of the conduit. I

The deformed portion ll functions substantially 40 'in the manner. of a Venturi tube for purposes of a reducing the pressure ofthegas while passing through the constricted conduit portion IL The expanding portion I6 is inop'en communication 7 with the atmosphere, and hence the exhaust gas passing through the constricted conduit portion it is under lessthanatmospheric pressure.

A casing 20 is provided about the constricted conduit portion l4 and is provided with inlet and outlet connections 2i and 22, respectively, for communication with the closed compartment which is to be heated. Thus air can be admitted into the casing 20 through the inlet connection" L til and carried from the outlet connection 22-. to

the compartment.

. :rhe airis nehetea through the casing 20 at substantially atmospheric pressure, and elicompas'ses the outer wall of the constricted portion I at a pressure which is higher than that of the exhaust gas passing through the interior of the constricted portion l4. Thus if any openings occur lnthe wall of the constricted portion It the diflerence in pressure upon the opposite" sides thereof will prevent movement 1ofexhaust gases through such openings into the interior 01' the casing and possible contamination of theair circulating in connection with the compertinent is-preventedr I i If it is desired to convey the exhaust gases to 1B amore remote point of discharge, an enlarged conduit l8 may be connected to the expanding portionfas at l1, by weldi-ng or some other suitable, method. Figs. 3, 4 and '5 illustrate another form of the 20 invention, wherein motor exhaust conduit! of uniformvtubular. shape is provided with a pairof diametrically opposed openings 3D through .its.sidewalls. I

Anairconduit 32, connected iri open communizs cation with the compartment to-be heated, is

provided with a partially flattened portion 34.

disposed within the openings 30 and extending through'the exhaust gas conduit in transverse relation therewith. There is thus provided a pair of constricted passages for the exhaust gas between the flattened portion 34 and the wall, of

the conduit Ill; The flattened portion is provided with v-shaped gas deflectingmembers 36 at the'front and rear edges thereof for guiding 35 the exhaust gas toward 'and away fronrthe constricted passages 35 and for cooperation withopposite portions of the wallof the cond t 2'.ii to provide a pair of tapering sections which. are siinilarto thereducing and expanding portions and I6 of the e aust conduit of the form'of -construction illustr ted in Fig. 1. The pair of constricted passages function in a manner.

similar to the constricted opening I in the form ofconstruction illustrated in Fig. 1, because the a combined cross seitional areas of the pair oi passages 35 is subs antially less: than the unobstructed cross sectional area of the conduit 25. Thus, the pressure in the exhaust gas as it is passing through the constricted. passageways 35 is less than the pressure in the air within the conduit portion 34, and movement of exhaust gas through any openinss that may occur in the wall 0 the air conduit member 34 and into 'the air st 'therein will be preyented by the pressure differential upon the opposite\sides of the conduit wall.

In constructing a device in accordance with this invention it is important that no restriction is oflered to the flow of air through-the zone of w juxtaposition withethe gas conduit whereby a reductionfin the pressure in the air at that point would result to' offset in some degree the pres-- sure diflereritial produced by the constriction or the, exhaust gas conduit. Therefore, that portion of the air conduit member which-is exposed 7o conduit. 1

in-Flg. 1, the relatively con.-

" the ratio of gas velocity and pressure withinthe constricted portion M to the velocity and pres-. sure of the gaswhile passing through the expanded discharge member It depends only upon the ratio of the crosssectional areas otthese two portions. v

Itis preferable, in order to obtain: maximum operating efliciency in a deviceof this invention, thatthe exhaust gases pass through the constrictedportion in, the form of a smooth flowing stream. In some type of motor installations 10.

- the exhaust gases are delivered in a pulsating J manner, and to counteract this condiition and to provide a smoot flow of gas to the heat exchanger it may be desirable to incorporate a gas storage reservoir 40- in the exhaust conduit be- I5 tween. the motor and the constricted portion or heater. To insure positive circulation of the air through the heater, any conventional means may beemployed in connection with the device, such 'as a thermosyphou closed circuit arrangement 20 or mechanical air-pro in k means? (not shown). Such mechanical propelling means,' such as a fan or pump, when used in conjunction with the constricted portion will increase the pressure difierentialin favor of the air stream 25 flowing into the passenger compartment. This will provide for further safetyhn avoiding contamination of the. preferred fluid-stream, which in the case of an automobile heater is the supply of fresh warm air being provided for passenger 30 consumption Such means may; however, be. used solely and indep'endently of the constricted portion f or insuring the higher pressure "being placed on the fresh air stream.

Thus, the means forcreating "'ferential in favor of the preferred fluid stream may be arranged to act upon either fluid stream, and may 'be either mechanical or non-mechanical. When-mechanical means are used in the pressure difv35 conjunction with the fluid beingtreated, the fan 40 or the like would preferably he so positioned as to cause a bulld up of pressure in point of heat exchange relation; ;and if mephanibal means are employed in connection with the other fluid, the fan orthe like would be ar- 5 ranged at the discharge end of the fluid conduit so as to urge the withdrawal of the fluidto provide a reduction of the-pressure in. the-fluid at the point of heat exchange relation.

invention haae been-shown and; described in detail, it'will be apparent to those skilled in the' art that the invention is not so limited but that varie Although only a limited number of torms'of the .ous'changm may be made therein without de-, parting from the spirit of the invention or from the scope of ,theappended claims.

What is claimed is: 1 1. In a heat exchange device for transferring 'heat'fromone fluid to another, a conduit for .the' treating arranged in heat exchange relation with; said a conduit solely irr theregion, of the constricted portion of said Venturi-like portion of said con duit, the outlet end of said conduit being ex- 65 panded and extended: whereby the pressure .of J

the fluid in said constricted portion of said 'conduit is normally reduced so that danger of leakage from, the treating fluid to the treated sum is minimized.

' 2. Inns-heat exchange device for transfer-rid: heat from one fluid to another, a conduit for the treatingfiuid in said conduit'providing a constriction therein for producing .aQVenturifluid having a portion in the form of a Venturi tube, a chamber for the'treatedflu'id like efiect saidineansinchidipg a port on, e15:

second conduit fortreatedfluid, said portion of v said second conduit having its wall exposed to the treating fluid at said constriction only, whereby the pressure of the fluid in said constricted portion of said conduit is-normally reduced so that danger of leak-age from the treating fluid to the treated fluid is minimized.

3. In a heat exchange device for transferring heat from one fluid to another, a conduit for the treating fluid, means extending through said conduit and' dividing the latter into a pair of fluid passages oi Venturi-like form, said means including a conduit for treated fluid, thesecoud mentioned conduit constituting wall portions of said passages solely at the constricted portions thereof, theinlet and outlet ends of said passages expanding from said constricted portions thereof.

4. In a heat exchange device for transferring heat from. one fluid to another, a conduit for I the treating fluid, a chamber for the treated fluid said conduit solely at the reduced pressure region thereof in advance of the expanded and extended portion. m o

- JOBEIgH M. GWINN, JR.

reduced, and said chamber being arranged on 

